1. Field
The present disclosure generally relates to additive manufacturing processes, and deals more particularly with a method and apparatus for 3-D printing a part in free space using part levitation.
2. Background
Additive Manufacturing (AM) is a process that creates physical parts directly from a 3-D (three dimensional) CAD (computer aided design) file using computer controlled additive fabrication techniques. Common AM techniques, sometimes also referred to as 3-D manufacturing, include stereolithography (SLA), fused deposition modeling (FDM), selective laser sintering (SLS) and three dimensional printing (3-DP), to name only a few. Each of these processes builds a three dimensional solid part, layer-by-layer, by locally fusing or curing building materials that may be in powder or liquid form.
Each of the AM processes mentioned above employs a “bottoms-up” building method in which the part is built layer-by-layer on a supporting platform that moves down as the individual layers are formed. A single print head is moved around the platform to form each of the layers. In some cases, it is necessary to build the part on support materials which must be later removed from the part. The need for a platform and support materials to stabilize the part limits the geometry and/or features of a part that can be fabricated. Moreover, the use of a single print head to form features of each layer renders the fabrication process relatively slow.
Accordingly, there is a need for an AM method and apparatus that eliminates the need for a platform and/or support materials to stabilize the part during the fabrication process, and which removes limitations on the types of features that can be formed, allowing full body 3-D printing of complex parts. There is also a need for a method and apparatus of the type mentioned above which increases the speed of the fabrication process.